Removal of heavy metal ions from wastewaters: A review

Heavy metal removal from water/wastewater by nanosized metal oxides: a review.

A positive temperature coefficient is the term which has been used to indicate that an increase in solubility occurs as the temperature is raised, whereas a negative coefficient indicates a decrease in solubility with rise in temperature.

Effect of Temperature

We report a novel procedure to synthesize a new type of water separation membrane using graphene oxide (GO) nanosheets such that water can flow through the nanochannels between GO layers while unwanted solutes are rejected by size exclusion and charge effects. The GO membrane was made via layer-by-layer deposition of GO nanosheets, which were cross-linked by 1,3,5-benzenetricarbonyl trichloride, on a polydopamine-coated polysulfone support. The cross-linking not only provided the stacked GO nanosheets with the necessary stability to overcome their inherent dispensability in water environment but also fine-tuned the charges, functionality, and spacing of the GO nanosheets. We then tested the membranes synthesized with different numbers of GO layers to demonstrate their interesting water separation performance. It was found that the GO membrane flux ranged between 80 and 276 LMH/MPa, roughly 4–10 times higher than that of most commercial nanofiltration membranes. Although the GO membrane in the present deve...

Enabling graphene oxide nanosheets as water separation membranes.

Graphene-based materials are gaining heightened attention as novel materials for environmental applications The unique physicochemical properties of graphene, notably its exceptionally high surface area, electron mobility, thermal conductivity, and mechanical strength, can lead to novel or improved technologies to address the pressing global environmental challenges This critical review assesses the recent developments in the use of graphene-based materials as sorbent or photocatalytic materials for environmental decontamination, as building blocks for next generation water treatment and desalination membranes, and as electrode materials for contaminant monitoring or removal The most promising areas of research are highlighted, with a discussion of the main challenges that we need to overcome in order to fully realize the exceptional properties of graphene in environmental applications

Motoi Machida

Papers

Lead(II) adsorption onto the graphene layer of carbonaceous materials in aqueous solution

Effect of ZnO loading to activated carbon on Pb(II) adsorption from aqueous solution

Adsorption of heavy metals onto activated carbons derived from polyacrylonitrile fiber.

Cadmium(II) adsorption using functional mesoporous silica and activated carbon.

Influence of activated carbon surface acidity on adsorption of heavy metal ions and aromatics from aqueous solution